NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: re Lars Tornqvist nav program - misch hints
From: Lars Tornqvist
Date: 2002 Feb 6, 12:38 -0000
From: Lars Tornqvist
Date: 2002 Feb 6, 12:38 -0000
Hi Peter, George and others Unfortunately the Sight program will only run on a Windows platform as it is written in Visual Basic! Also I have no experience with Mac so I can't tell if these Super Mac's are able to do it? - Timing : At present the computers clock must be set to GMT to run in 'Real-Time-Mode' This I will make user definable asap as others have asked the same question. For now you can key in any time and date you wish and also Simulate the sky movement - BUT if you check the checkbox "Use PC-clock" the computers time will be used as GMT - be patient I will correct this matter! - Accuracy: The Sun Moon and Planets will be accurate back in time - how long I don't know - but believe 100 years back will give you an accuracy of the Sun within 2-3 arcmin but Moon and Planets perhaps more! I havn't checked it out - but let me know of your findings. The Stars on the other hand, are not udated for Proper Motion and Apparent movement YET - (this might be done next week) Therefore don't rely on the Stars within +/- 2 years Latitude and Logitude input: You can use any postion you wish - the way to input deg.min.tens are done this way: 120�34'5 E = -120345 : 075�45'6 W= 75456 : 55�23'6 S = -55236 etc etc. North and West are Plus(+) I will include later the option to select which Lat or Long to be Plus or Minus The above way to input deg.min.tens are the same with sextant inputs Regsrds Lars ----- Original Message ----- From: Peter FoggTo: Sent: Wednesday, February 06, 2002 5:52 AM Subject: re Lars Tornqvist nav program > Looks very interesting, Lars, and must represent a huge amount of work. > > a few queries: > > Will it run on Macintosh computers? > > Is it independant of the correct GMT being displayed on the computer's > clock? Mine is decidedly inaccurate, although it is regularly updated to > this local time. Can the relevant local time only, with the appropriate > correction, be used? > > I enjoy solving (or not) the navigational problems such as the 'Silicon > Sea' series on the Nav. list. These can involve data from all over the > world and any time zone, and any year. My own approach is to always > start with local time and convert to GMT when necessary. Could your > program cope with these parameters? For example, I note that the almanac > is good for the next 10 years but how far back does it go? > > Your example shows an assumed postion in whole degrees. How would it > cope with a DR position that may involve one tenths of a minute of long. > or lat. ? (Personally I think that a DR to the nearest minute is all > that is needed or practical but the problem being worked on may use > greater precision) >